Interesting article.
Basically, we decreased air pollution aerosols successfully, but that type of pollution had a cooling effect. So once they were removed, we weren't being shielded as well from the greenhouse gas-related heat, and greenhouse gas emissions are still going up and haven't yet reversed. So we're getting the full brunt of the heat from that now without aerosols from air pollution mitigating it.
The scientist's outlook in this is that that was predicted by their models, that getting rid of the aerosols first would cause it to get warmer, which perhaps suggests their other models have some degree of reliability.
